a. Field of the Invention
The present invention relates to a measuring apparatus, and more particularly to a measuring machine for measuring length, thickness, width or the like of an object to be measured.
b. Description of the Prior Art
In a conventional measuring machine for use with a measuring device, such as a micrometer, a dial guage or the like is employed to measure precisely an object having a relatively large dimension. Thus, the measuring machine is, generally, provided with a stationary measuring contact point and a movable measuring contact point positioned so as to oppose the stationary contact point. A sliding member is in the form of a spindle carrying the movable contact point and a guiding member guides the spindle to make the movable measuring contact point approach or back away.
In the conventional measuring machine of the dial-guage type, the sliding member is conveyed toward the stationary measuring contact point in order to measure the dimensions of the object. The sliding member is conveyed along with the guiding member. The guiding member is, generally, provided with rollers, each of which is positioned at both end portions of the guiding member.
In the conventional measuring machine, a clearance is provided between the sliding member and a bearing unit with the aim of permitting a sliding motion of the sliding member. By the presence of clearance, the sliding member is inevitably slid and thereby the uniform and precise measuring value can not be obtained. By the swinging motion of the sliding member in the form of the spindle, sliding friction acts on the spindle to decrease the smooth forward and backward movements of the spindle and, therefore, a large amount of actuating force is necessary because of the sliding friction acting on the spindle.